1. Field of the Invention
The present invention relates to a method and a device for the initial flushing of a blood treatment apparatus.
2. Description of the Related Art
It is known that before commencing dialysis treatment, the dialyser has to be flushed and filled (procedure referred to as priming) by passing a flushing solution through the compartments of the dialyser. Various methods have been proposed for carrying out this flushing. For example, U.S. Pat. No. 5,004,548 describes a method which consists in connecting the outlet of the dialyser's blood compartment to the inlet of the dialysis liquid compartment, and in circulating in series, through the blood compartment and the dialysis liquid compartment, a sterile physiological saline solution issuing from a bag. The outlet of the dialysis liquid compartment is connected to a bag for collection and discharge of the flushing liquid.
In a known flushing method, the flushing liquid is not recovered in a collecting bag, but is eliminated via the dialysis apparatus' pipes for discharge of used liquid. For this purpose, the outlet connection piece of the dialysis liquid compartment is connected, by way of a conduit and an electromagnetic valve, to a discharge pipe provided in the dialysis apparatus in proximity to the outlet of an ultrafilter. At the same time, a dialysis liquid is circulated through the ultrafilter, so that the liquid for flushing the dialyser and the dialysis liquid in preparation are thus discharged together in the discharge pipe.
The advantage of this solution is that it permits considerable savings to be made, by omitting the collecting bag and avoiding the expenses involved in disposing of the latter, and it permits an improvement in the flushing of the dialyser. In addition, there is no risk of the dialyser or of the sterile parts of the apparatus being contaminated by the non-sterile liquid since there is complete separation of the sterile and non-sterile parts of the apparatus.
To ensure satisfactory flushing of the dialyser, any air bubbles present on the membrane of the dialyser have to be eliminated. To do this at the present time, the person charged with performing the dialysis gently taps the dialyser so that the bubbles dislodge from the membrane and are discharged with the flushing liquid.
An object of the invention is to perfect the flushing method indicated above, in such a way as to render it completely automatic, while at the same time retaining the advantages of the known flushing method described hereinabove.